Seven-Digit Singer Serial Number?
My wife has a beat-up portable Singer in her sewing room, just for display. I recently decided I needed a new hobby and bought a 1928 Singer 66-6 to fix up, and then decided I should look more closely at my wife's machine, too.
The first thing I did was look at the serial number, and found it had 7 digits, but I have not been able to find any reference to Singer numbers that long. The last digit looks like it might have been struck more lightly than the others and I'm wondering if it is just a double-strike. That would make identifying the machine easier, except that the resulting model for that serial number using the ISMACS database would be a Model 15 made in 1910. Using the Sandman-Collectables machine identification guide, it identifies the machine as a 66-16.
Even if I keep the last digit and delete the leading zero, the database still identifies it as a Model 15. Have there been any other known occurrences of 7-digit serial numbers?